Phagocytic activity of the leukemic cell and its response to the phagocytosis-stimulating tetrapeptide, tuftsin.

tuftsin activity in the sera of patients was also evaluated. Fifteen patients were included in this study: six with myelofibrosis, seven with acute granulocytic leukemia, and two with myelomonocytic leukemia. In all six cases of myelofibrosis, the polymorphonuclear cells showed a normal level of basal phagocytosis in Krebs-Ringer phosphate glucose medium. Five of seven cases of acute granulocytic leukemia showed normal or near-normal values also, while two had significantly diminished levels. All thirteen of these patients failed to show stimulation with saturating amounts of autologous serum or tuftsin. This is distinctly abnormal, since normal blood granulocytes of humans, dogs, and rabbits are considerably stimulated. The two cases of myelomonocytic leukemia available for study showed a higher than normal basal phagocytic activity in Krebs-Ringer phosphate glucose medium and responded normally to serum and tuftsin stimulation.